ASTM F568M

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ASTM F568M is an ASTM International standard for metric bolts, screws and studs that are used in general engineering applications. It is titled: Standard Specification for Carbon and Alloy Steel Externally Threaded Metric Fasteners. It defines mechanical properties for fasteners that range from M1.6 to 100 in diameter. The standard was withdrawn in 2012.[1] and has been replaced by ISO 898-1[2]

This standard defines property classes, the metric equivalent of a screw grade, that are almost identical to those defined by ISO 898-1,[2] except for the addition of the 8.8.3 and 10.9.3 classes. These two additional standards are fasteners that have the same mechanical properties as their base property class (i.e. 8.8 and 10.9), but are made from weathering steel.[1][3]

This is a standard set by the standards organization ASTM International, a voluntary standards development organization that sets technical standards for materials, products, systems, and services.

Mechanical properties[edit]

Head markings and mechanical properties[4]
Head marking Grade, material & condition Nominal thread diameter size range [mm] Proof strength [MPa] Yield strength (min) [MPa] Tensile strength (min) [MPa] Core hardness [Rockwell]
Hex cap screw-class 4.6.svg Class 4.6
Low or medium carbon steel
5–100 225 240 400 B67–95
Hex cap screw-class 4.8.svg Class 4.8
Low or medium carbon steel; fully or partially annealed
1.6–16 310 340 420 B71–95
Hex cap screw-class 5.8.svg Class 5.8
Low or medium carbon steel; cold worked
5–24 380 420 520 B82–95
Hex cap screw-class 8.8.svg Class 8.8[5]
Medium carbon steel; quench and tempered
Under 16 (inc.) 580 640 800 C18-31
17–72 600 660 830 C23–34
Hex cap screw-class 8.8 line.svg Class 8.8 low carbon
Low carbon boron steel; quench and tempered
Hex cap screw-class 8.8.3.svg Class 8.8.3[1]
Atmospheric corrosion resistant steel; quench and tempered
Hex cap screw-class 9.8.svg Class 9.8
Medium carbon steel; quench and tempered
1.6–16 650 720 900 C28–37
Hex cap screw-class 9.8 line.svg Class 9.8 low carbon
Low carbon boron steel; quench and tempered
Hex cap screw-class 10.9.svg Class 10.9
Alloy steel; quench and tempered
5–100 830 940 1040 C32–39
Hex cap screw-class 10.9 line.svg Class 10.9 low carbon
Low carbon boron steel; quench and tempered
Hex cap screw-class 10.9.3.svg Class 10.9.3[1]
Atmospheric corrosion resistant steel; quench and tempered
Hex cap screw-class 12.9.svg Class 12.9
Alloy steel; quench and tempered
1.6–100 970 1100 1220 C39–44

See also[edit]

References[edit]

  1. ^ a b c d ASTM F568M - 07, retrieved 2009-06-10 .
  2. ^ a b ISO 898-1:2009, 2009-04-01, retrieved 2016-04-13 .
  3. ^ Bickford & Nassar 1998, p. 154.
  4. ^ Metric Handbook, archived from the original on October 31, 2007, retrieved 2009-06-06 .
  5. ^ Bolt grade markings and strength chart, retrieved 2009-05-29 .

Bibliography[edit]